Regulating device for watches



Jan. 12, 1943. F. MART! 2,307,841

REGULATING DEVICE FOR WATCHES Filed Nov. 27, 1940 Patented Jan. 12, 1943 REGULATING DEVICE FOR WATCHES Fritz Marti, La Chaux de Fonds, Switzerland Application November 27, 1940, Serial No. 367,480 In Switzerland December 15, 1939 4 Claims.

The present invention relates to a regulating device for watches of the type having a balance wheel and a spiral spring. It is characterized by the feature that the active length of the spiral spring is automatically increased when the amplitude of the balance wheel exceeds a predetermined value, in order that the increase of the period due to the increase of length of the spiral spring compensates for the diminution of the period due to the increase of amplitude.

The accompanying drawing represents a common regulating device and two embodiments of the invention.

Fig. 1 is a diagrammatic plan view of the common regulating device having a balance wheel and a spiral spring.

Figures 2 and 3 are diagrammatic plan views illustrating each one of the above embodiments.

In Figure 1, the reference character I indicates the axle of the balance wheel, and 2 indicates the spiral spring or hairspring the inner extremity of which is fixed by a ferrule to the said axle, while the outer extremity is fixed to the ring hook 3 which is itself fixed to the frame. 4 is the regulator lever which may be turnable about the axle of the balance wheel and which carries two pins 5 and 6 between which passes the hairspring. The active length of the spiral is comprised between the said pins and the inner end of the spiral. 001 indicates the position of rest of the balance wheel. 0A1 indicates the extreme right hand position and 0A2 the extreme left hand position. The angle O1-OA1 or O1OA2 is the amplitude, and T may be the period or time required by the balance wheel to travel from 0A1 to 0A2.

As already known, this period T depends also upon the active length of the hairspring and is raised with this length, a fact which permits of general retouching of the balance wheel-spiral system by turning the regulator lever in clockwise or counter-clockwise direction. Further, it is known that in the case the balance wheel oscillates alone, its oscillations are isochronous the period T being thus independent of the amplitude, while when the balance wheel is combined with an escapement the face of things changes. Generally the effect of the escapement is to diminish the period in the event of great amplitudes so as to cause the watch to advance while in the event of small amplitudes it increases the period thus causing the watch to retard. On the other hand upon winding up of the watch maximum amplitudes of the balance wheel are obtained because in that moment the escapement acts with maximum force upon the balance wheel. The result of this arrangement is that a watch with barrel of 24 hours advances in the morning and retards at night, so that finally, at the end of the day, the watch will indicate the exact time. However, in cases of watches having a barrel of eight days or even thirty days the advancing will continue several days through and the advancing of the first day will be added to the advancing of the following days thus causing differences of an inadmissible extent.

The embodiment hereinafter described aims to overcome these inconveniences.

In the embodiment of Fig. 2 the regulator lever 4 is shown carrying two ears I and 8. To the ear I is fixed a rigid abutment pin 9 which lies inside the hairspring near the outer end section thereof. On the ear 8, between the ear 1 and the fixed point 3 of the hairspring is rotatably mounted a disk ID carrying a rigid abutment pin II which is disposed outside said spring near the outer end section thereof. The distance between the pin H and the hairspring may be adjusted by turning the disk [0.

In the rest position of the balance wheel, the hairspring bears slightly against the two pins 9 and I l. There is no pin play in contradistinction to the arrangement shown in Figure 1.

In the event of little amplitudes the active length of the hair spring which bears against the pin 9 terminates in this point. When the amplitudes increase the spring gets oil the pin 9 during its opening travel and, in this moment, comes to bear against the pin H thereby increasing its active length to an extent equal the distance 1 between said pins, the result being an increase of the period of the balance wheel. It will be seen that this increase is suflicient to annul the diminution of this period due to the increase of amplitude.

In the embodiment of Fig. 3 the regulator lever 4 is shown having only one ear l2 extending alongside the hair spring and carrying on one of its ends a rigid abutment pin 9. On the other end of said car, there is arranged a series of three holes I3 adopted to engage the pin H, so as to permit of varying the length I which the spring is automatically increased.

Evidently, the difierent features of the embodiments illustrated in Figures 2 and 3 may be combined. For instance, the pin 9 of Figure 3 could be mounted on a disk as is the case with pin II in Figure 2, which is shown integral with the disk H); such an arrangement facilitates the adpermit said coil by its expansion to move away I from said inner curb member and to be curbed merely by said outer curb member so as to have its operative length automatically increased to an extent corresponding to the angular distance between said both curb members.

2. A watch-regulator comprising, a hairspring for a balance wheel, a pivoted regulator lever for said hairspring, said lever being formed with a rigid arm extending radially therefrom, a fixed curb member secured to said arm and bearing only against the inner side of the outer coil of said hairspring,- a second curb member bearing only against the outer side of said coil, saidsecond curb member being disposed in spaced angular relation to said first curb member so as to permit said coil by its expansion to move away from said inner curb member and to be curbed merely by said outer curb member so as to have its operative length automatically increased to an extent corresponding to the angular distance between said both curb members, and a device for adjusting the position of said outer curb member.

3. A watch-regulator comprising, a hairspring for a balance Wheel, a pivoted regulator lever for said hairspring, said lever being formed with two arms extending radially therefrom and being disposed in spaced angular relation to each other, a fixed curb member secured to one of said arms and bearing only against the inner side of the outer coil of said hairspring, a disk pivoted on the other of said arms, a second curb member eccentrlcally secured to said disk and bearing only against the outer side of said coil, said coil being adapted by its expansion to move away from said inner curb member and to be curbed merely by said outer curb member so as to have its operative length automatically increased to an extent corresponding to the angular distance between said both curb members.

4.-A Watch-regulator comprising, a hairspring for a balance wheel, a pivoted regulator lever for said hairspring, said lever being formed with a cranked arm extending radially and peripherical- 1y therefrom, a fixed curb member secured to the radial portion of said arm and bearing only against the inner side of the outer coil of said hairspring, the peripherical portion of said arm having a series of holes, a second curb member engaged in one of said holes and bearing only against the outer side of said coil, said coil being adapted by its expansion to move away from said inner curb member and to be curbed merely by said outer curb member so as to have its operative length automatically increased to an extent corresponding to the angular distance between said both curb members.

FRITZ MARTI. 

